How to make Win7 as an NTP server

1. Modify the registry keyHkey_local_machine\system\currentcontrolset\services\w32time\timeproviders\ntpserver        Enabled is set to 1 (default 0)hkey_local_machine\system\currentcontrolset\services\w32time\config\        announceflags set to 5 (Default 10)

Timeserv_announce_no, Reliable_timeserv_announce_no. The domain controller does not advertise time service.

TD colspan= "1" >

value	meaning
0
1	Timeserv_announce_yes. The domain controller always advertises time service.
2	Timeserv_announce_auto. The domain controller automatically determines whether it should advertise time service.
4	Reliable_timeserv_announce_yes. The domain Contoller would always advertise reliable time service.
8	Reliable_timeserv_announce_auto. The domain controller automatically determines whether it should advertise reliable time service.

2. Disable the firewall or set exceptions for UDP 123 ports. 3. Run services.msc to set the Windows Time service to Automatic (delayed start)Win7 if set to Automatic, the service will be stopped after the next reboot for an unknown reason. After the experiment, the delayed start does not require the user to log on to start. 4. Restart the school services: net stop W32Time && net start W32Time network devices such as Cisco, H3C switches ... ) cannot synchronize NTP server time: Hkey_local_machine\system\currentcontrolset\services\w32time\config\localclockdispersion value modified to 0 (default = 0x0000000a) Reference URL: http://support.microsoft.com/kb/314054/zh-cnhttp://technet.microsoft.com/en-us/library/ cc784191.aspxhttp://technet.microsoft.com/en-us/library/cc773263 (ws.10). aspxhttp://technet.microsoft.com/en-us /library/cc773013 (v=ws.10). aspxhttp://www.dotblogs.com.tw/clark/archive/2012/01/02/64146.aspxhttps:// social.technet.microsoft.com/forums/windowsserver/en-us/ffb1df0b-7c6e-4b2d-8fdf-b4ca0c014266/ Configuring-windows-7-as-an-ntp-server?forum=winserverpnhttp://wenku.baidu.com/link?url= 0b8zecpnbeiybx-z-5sn3bzouegsaeug3rfpqksrnus4i6_rwvjj0mkcfoziu-weypcqvp5fajqdxi47u_eqpxmxaogio0ys9v9xgtjnpac

A second note:

(Excerpt from HTTP://SUPPORT.MICROSOFT.COM/KB/816042/ZH-CN)

1. Change the server type to NTP. To do this, follow these steps:

A. Click Start, click Run, type regedit, and then click OK.
B. Locate and click the following registry subkey:
Hkey_local_machine/system/currentcontrolset/services/w32time/parameters/type
C. In the right pane, right-click the Type, and then click Modify.
D. In edit value, type NTP in the Value data box, and then click OK.

2. Set the AnnounceFlags to 5.  To do this, follow these steps: A. Locate and then click the following registry subkey:
Hkey_local_machine/system/currentcontrolset/services/w32time/config/announceflags
B. In the right pane, right-click AnnounceFlags, and then click Modify.
C. In the edit DWORD value, type 5 in the Value data box, and then click OK.

3. Enable NTPServer.  To do this, follow these steps: A. Locate and then click the following registry subkey:
Hkey_local_machine/system/currentcontrolset/services/w32time/timeproviders/ntpserver
B. In the right pane, right-click Enabled, and then click Modify.
C. In the edit DWORD value, type 1 in the Value data box, and then click OK.

4. Specify a time source.  To do this, follow these steps: A. Locate and then click the following registry subkey:
Hkey_local_machine/system/currentcontrolset/services/w32time/parameters/ntpserver
B. In the right pane, right-click NtpServer, and then click Modify.
C. In edit value, type peers in the Value data box, and then click OK.

Note: Peers is a placeholder that should be replaced by a space-delimited list of peers from which your computer gets the timestamp. Each DNS name that is listed must be unique. Must be appended to, 0x1 after each DNS name. If you do not append, 0x1 after each DNS name, the changes that you made in step 5 will not take effect.

5. Select the polling interval.  To do this, follow these steps: A. Locate and then click the following registry subkey:
Hkey_local_machine/system/currentcontrolset/services/w32time/timeproviders/ntpclient/specialpollinterval
B. In the right pane, right-click SpecialPollInterval, and then click Modify.
C. In the edit DWORD value, type TimeInSeconds in the Value data box, and then click OK.

Note: TimeInSeconds is a placeholder and should be replaced with the number of seconds between polls you want. The recommended value is 900 (decimal). This value configures the time server to poll every 15 minutes.

6. Configure the time calibration settings.  To do this, follow these steps: A. Locate and then click the following registry subkey:
Hkey_local_machine/system/currentcontrolset/services/w32time/config/maxposphasecorrection
B. In the right pane, right-click MaxPosPhaseCorrection, and then click Modify.
C. In the edit DWORD value, click in the Cardinality box to select Decimal.
D. In the edit DWORD value, type TimeInSeconds in the Value data box, and then click OK.

Note: TimeInSeconds is a placeholder that should be replaced with the appropriate value, such as 1 hours (3600) or 30 minutes (1800). The value you select will vary depending on the polling interval, network condition, and external time source.
E. Locate and click the following registry subkey: Hkey_local_machine/system/currentcontrolset/services/w32time/config/maxnegphasecorrection
F. In the right pane, right-click MaxNegPhaseCorrection, and then click Modify.
G. In the edit DWORD value, in the Cardinality box, click to select Decimal.
H. In the Edit DWORD value, type TimeInSeconds in the Value data box, and then click OK.

Note: TimeInSeconds is a placeholder that should be replaced with the appropriate value, such as 1 hours (3600) or 30 minutes (1800). The value you select will vary depending on the polling interval, network condition, and external time source.

7. Exit Registry Editor.
8. At the command prompt, type the following command to restart the Windows time service, and then press Enter:
net stop W32Time && net start W32Time


In general, we do not need to build a time server, directly from the most accurate time on the Web server to obtain time.
Individuals think that China's time than the United States, Microsoft is more than Red Hat and European Linux quasi, because of the speed, the smaller the delay the more accurate.

Time synchronization first time servers are more accurate (stratum 1), Level two time servers (stratum 2) 、......、 15-level time servers (stratum 15).
Stratum 1:
210.72.145.44 National Timing Center, CAS
S1a.time.edu.cn Posts and Telecommunications
S1b.time.edu.cn Tsinghua University
S1c.time.edu.cn Peking University
s1d.time.edu.cn Southeast University
S1e.time.edu.cn Tsinghua University
time.windows.com US Microsoft

How to make Win7 as an NTP server